The orchid family (Orchidaceae) is the second largest family of flowering plants with approximately 20,000 species. Some estimates for the size of this family are higher, but the sunflower family (Asteraceae) is now considered the largest with nearly 24,000 species. With the exception of numerous varieties of exquisitely beautiful blossoms which are sold commercially, the only economically important product in this great plant family is the delicious spice known as vanilla. Vanilla comes from several species of perennial vines of the genus Vanilla native to Mexico and tropical America. The vines commonly climb on the trunks of trees or poles by means of adventitious (aerial) roots. The primary source of commercial vanilla comes from V. planifolia, also listed in many references as V. fragrans. Another lesser known species is West Indian vanilla (V. pompona). The Aztecs originally used vanilla as a flavoring for chocolate, and the Spanish conquerers carried it back to Europe where it was used for this same purpose.

A vanilla orchid vine (Vanilla planifolia) with flower buds.

Vanilla extract is obtained from the unopened seed capsules (called vanilla beans) which superficially resemble bean pods. The unopened pods are picked when the color changes from green to yellow. The pods are placed in the sun for up to five hours, then they are tightly wrapped in blankets and placed in airtight boxes to sweat. This process is repeated for up to 36 days. During this curing process the pods undergo fermentation and turn black in color. After the laborious curing process, the pods are thoroughly dried. The long fermentation process causes several glucosides (including glucovanillin) to decompose into glucose and vanillin. Vanillin is the aromatic phenolic compound which produces the characteristic aroma and flavor of vanilla . It is extracted from chopped up vanilla beans in an ethanol-water mixture to yield the vanilla extract of commerce. Vanillin is also synthesized from other compounds, such as eugenol from oil of cloves, and as a by-product from the breakdown of lignin in the manufacture of paper from wood pulp. Extracts of vanillin derived from sources other than vanilla beans are usually labeled "imitation vanilla." Vanilla bean extract is more expensive, but has a better flavor than imitation vanilla. According to the excellent recommended text for this course (Economic Botany by B.B. Simpson and M.C. Ogarzaly (1995), an American biotechnology firm has developed a method of obtaining vanilla by culturing plant cells. This technology could greatly reduce the cost of growing vanilla beans, but could seriously effect the economy of vanilla-producing countries such as Madagascar, Java and Tahiti.

According to many chefs, bakers and vanilla connoisseurs, the best flavoring comes directly from the vanilla pods. They would never use imitation vanilla extract in their favorite recipes. There are apparently subtle ingredients in the real vanilla bean that truly enhance the flavor. Small pieces of the pulpy pod are added to various dishes and pastries for their unique flavoring. Also embedded in the pulpy pods are thousands of minute seeds. The tiny brown or black specks in vanilla ice cream indicate that real vanilla beans were used; however, similar specks from another source could be used in imitation ice creams. As a flavoring for cream-filled chocolates, toppings, beverages, cookies, cakes, pies, puddings and ice creams, vanilla is unsurpassed. Vanilla extract adds a delicious fragrance to candles, creams, perfumes and lotions. It is also used pharmaceutically for flavorings in medicines, and to treat loss of appetite.

Many species of orchids have showy, intricately-shaped flowers that require special pollinators, and the vanilla orchid is no exception. Throughout the tropical regions where this remarkable orchid is cultivated, including Madagascar, Seychelles Islands, Java and Polynesia, the flowers are always pollinated by hand. Even in its native habitat of Mexico, cultivated orchids are pollinated by hand since natural pollination occurs in less than one percent of the blossoms. It has been postulated that hand pollination was also practiced by the Aztecs in order to maintain the populations of these remarkable orchids. The inflorescence (raceme) bears 20 or more flowers which open in succession, each flower lasting one day. Hand pollination involves the pressing of pollen masses (pollinia) into the stigmas of flowers. Entire vanilla plantations must be hand-pollinated every morning during the blooming season, and a trained pollinator can transfer pollen to 1,500 flowers per day.

Left: A vanilla orchid (Vanilla planifolia) with immature seed capsules (vanilla beans) in the greenish stage. Right: A mature vanilla seed capsule (vanilla bean) which has been fermented and dried. Depending on the brand, one or two beans are packed per bottle, and the bean can be used for many months. Imitation vanilla extract contains mostly pure vanillin derived from sources other than the vanilla orchid. Although it smells and tastes like vanilla, it is not as good as the extract from true vanilla beans.

Legume Family: Fabaceae

Tonka Beans (Dipteryx odorata)

Tonka beans: Dark, wrinkled seeds from Dipteryx odorata, a large tree from the rain forests of Brazil, Colombia and Venezuela. The seeds contain the fragrant phenolic compound coumarin which is used in perfumes and as a vanilla-like flavoring in ice creams, candy and pipe tobaccos. Coumarin is a double-ring phenolic compound that imparts the distinctive sweet smell to newly-mown hay. Although it enhances the flavor and aroma of tobaccos, coumarin has been shown to be carcinogenic when burned. Coumarin is also an anticoagulant that represses the synthesis of the protein prothrombin in the presence of vitamin K.

Inga edulis, a large tree native to tropical America with long, snakelike pods. Called "ice cream bean," the seed-bearing pods contain a sweet, fleshy, translucent pulp that is eaten by people in Ecuador.

Marijuana Family: Cannabaceae

Hops (Humulus lupulus)

The hop plant (Humulus lupulus) is a vine that was formerly placed in the mulberry family (Moraceae), but because of the remarkable similarity of floral characteristics, it is now placed in the marijuana family (Cannabaceae) along with marijuana or Indian hemp (Cannabis sativa). In fact, these are the only two genera in this family. Both species are dioecious, with separate male and female plants in the population. The females flowers of hop plants are strikingly similar to those of marijuana. Another example of their genetic affinity has been demonstrated by grafting the scion or shoot of a hop plant to the rootstock of marijuana. The purpose of this graft was to produce an unrecognizable hybrid with the appearance of a hop plant but with the THC of marijuana.

Like marijuana, male and female hop plants produce clusters of apetalous flowers. Each female flower is subtended by a leafy bract, and when mature, the female inflorescence superficially resemble a small, soft pine cone because of the numerous overlapping bracts. The bracts contain glands that produce the characteristic volatile oils of hops. The dried, mature conelike structures are also referred to as hops. They are added to beer because they impart a pleasant taste and aroma. Hops also contain enzymes that coagulate excess unwanted proteins that cause beer to become cloudy. Hops are very important in the beer industry because they help to produce a clear, sparkling brew. They also contain compounds that have antibiotic properties and help to prevent bacterial action and spoilage of beer.

The female flowers of marijuana (Cannabis sativa) are very similar to those of the hop plant (Humulus lupulus). Both species belong to the marijuana or hops family (Cannabaceae). Female flowers of both species are subtended by conspicuous bracts. Bracts of hop flowers are larger and they overlap each other to form a conelike structure called the "hop." Both species also contain numerous resin glands on the upper leaves and bracts. In marijuana, the golden, globular resin glands are the source of THC (delta-trans-tetrahyrocannabinol), the main reason this plant is the primary cash crop in many regions of the world (including several counties in California). Male marijuana plants are much less glandular and are commonly grown for their high quality stem fibers called bast fibers. They are cultivated and exported as an excellent textile fiber under the name of Indian hemp.

Marijuana is native to central Asia, and the Chinese appear to have been the first to harvest the plant for its hemp fibers and medicinal uses. The psychoactive properties of marijuana were first exploited in India. The Indians classified Cannabis products into ganja, consisting of the potent female flowers and upper leaves, and hashish, the golden resin containing THC. The most potent and resinous plants are bushy, well-spaced female plants grown in warm, sunny climates without male plants. The term "sinsemilla" (sin: without) and (semilla: seed) refers to unpollinated, unfertilized female plants without seeds. Through the travels of Marco Polo, Napolean and British colonists, the virtues of marijuana as a fiber plant and psychoactive drug spread to Africa, Europe and the New World. Marijuana has a number of therapeutic uses. It reduces the nausea experienced by cancer patients undergoing radiation and chemotherapy. Since THC dilates bronchial vessels, it provides relief for asthma sufferers. It also relieves hypertension, and is effective in reducing pressure in the eyes of glaucoma patients. Although it is illegal to grow without special medical permits, it is still the number one cash crop in some areas of the United States.

Left: Inflorescence of female marijuana plant (Cannabis sativa) showing elongate, 2-pronged stigmas and upper leaves covered with gland-tipped hairs which appear like small granules on the foliage. Center: Close-up view of female flower showing elongate 2-pronged stigma and lower subtending bract. The female flowers of the hop plant are very similar, except the bracts are larger and they overlap each other to form a conelike structure called the hop. Right: Microscopic view of the globular, gland-tipped hairs of a female marijuana plant. The golden resin glands are the source of THC (tetrahyrocannabinol), the main reason this plant is the primary cash crop in many regions of the world (including several counties in California).

Beer is made from fermented malt sugar (maltose) derived from germinated barley grains (Hordeum vulgare). Germinated barley is used because the starch polymers inside the starch grains have been converted (hydrolyzed) into maltose. The fermentation process is accomplish by yeast fungus of the genus Saccharomyces, including S. cerevisiae and other species. Ale and lager beers differ from regular beers in the kinds of Saccharomyces that are used. Ale is produced by S. cerevisiae at the top of large tanks, and usually has a higher alcoholic and hop content than regular beers. S. uuvarum is a bottom fermenter in large tanks and is used to produce lager and Pilsner beers. Pilsner beers have a strong hop component, while other beers are brewed with fewer hops and are less bitter. Stout is a dark beer made using roasted barley as well as malt sugar and contains at least 6 percent carmel for added color and body. Modern beer making is an elaborate and complex process involving exact timing and chemical control. It is explained in more detail in the recommended textbook for this course.

A female hop vine (Humulus lupulus) and an assortment of hops, the conelike inflorescences of female plants. The hops were collected in Oak Creek Canyon, Arizona from wild plants named H. americanus, a synonym for H. lupulus.

A female hop vine (Humulus lupulus) and the conelike inflorescences used in beer.

The ginger family (Zingiberaceae) includes some of the most beautiful flowers on earth. It also includes several economically important species, such as cardamom (Elettaria cardamomum), ginger (Zingiber officinale) and turmeric (Curcuma domestica). The dried, ground rhizome of turmeric (also listed as C. longa) is used in curry powder and as a yellow dye.

A hybrid species of Curcuma (turmeric). Like many other species in the tropical ginger family (Zingiberaceae), the flowers are very colorful and showy. The dried, ground rhizomes of the Asian species Curcuma domestica (also listed as C. longa) are the source of a yellow dye and the turmeric used in curry powder.

Korean ginseng root and drink (Panax ginseng) and American ginseng tea (P. quinquefolius). The fusiform taproot of both herbs is used as a refreshing tea that is reportedly a cure-all medicine in some Asian countries. The sliced roots of Asian ginseng are eaten raw and in salads. American ginseng grows wild in hardwood deciduous forests of the northeastern United States. It superficially resembles another herb in the aralia family (Araliaceae) called wild sarsaparilla (Aralia nudicaulis). See the following image.

Although widely distributed in tropical regions, the aralia family (Araliaceae) includes a number of native herbs in North America. This photo of wild sarsaparilla (Aralia nudicaulis) was taken in the understory of a Douglas fir forest (Pseudotsuga menziesii) near Flathead Lake, Montana. The taproot is used for an herbal tea and sometimes as an ingredient in root beer. True sarsaparilla flavoring comes from Smilax officinalis of the lily family (Liliaceae). Another North American species of aralia called American spikenard (A. racemosa) also has aromatic taproots that are used for a medicinal herbal tea.

Bignonia Family (Bignoniaceae)

Parmentiera (Parmentiera edulis)

Guajilote or guachilote (Parmentiera edulis), a spiny, central American tree closely related to the calabash tree (Crescentia alata). Like the calabash, the striking cauliflorous fruits of Parmentiera edulis are produced on the main trunk. This species is also listed in some references as P. aculeata. The elongate, banana-shaped fruits are quite sweet and are eaten raw, cooked, roasted, or made into pickles and preserves.